Subject: Re: [linux-audio-dev] hdr disk throughput
From: Paul Barton-Davis (pbd_AT_Op.Net)
Date: Mon Mar 13 2000 - 16:32:31 EST
>If I comment out the write, there is no drop in performance.
This is significant.
>I get about 4.5Mb of reads per second on my disk, either way.
I hope you have an old disk. For 24bit/96kHz we need 9MB/sec
uni-directional transfer :)
Thanks for thinking about this. It turns out that I have deeper
problems than this. This issue of (1) always having to read the
existing data combined with (2) having to always read-ahead has forced
me to have to drastically rethink the buffering system for ardour.
Not to mention doing cross-fades at punch-in points, which means
combining existing material and doing a little mix with the new stuff
for some period of time (typically 5ms-1.5sec).
I haven't, as yet, come up with a new scheme that will actually work
in the way I want to (i.e. absolute minimum number of data copies,
preferably one from disk to audio interface buffer and one in the
other direction, but I'll settle for 2 in each direction :)
>BTW, you might want to run them on a raw partition, and a
>filesystem, to compare performance.
I've ruled out raw partitions, they seem evil in almost every way. I
know they'd be faster, but I don't care - the other losses seem to great.
For now :)
--p
This archive was generated by hypermail 2b28 : Tue Mar 14 2000 - 00:15:35 EST